Abstract: In order to understand the impacts of acid rain on the community composition and diversity of small and medium-sized animals in lateritic red soil in Guangdong, a field plot experiment was set up, in which, the simulated acid rain was sprayed for 3 months, and the soil samples were collected once two weeks from December 1, 2008 to March 1, 2009. A total of 14997 small and medium-sized soil animals were captured, belonging to 4 phyla, 7 classes, and 13 orders. Nematoda was the only dominant group, accounting for 85.34%, and Collembola and Acarina were the common orders, occupying 13.46% of the total. There were 10 groups of rare orders, only taking a proportion of 1.2%. With the decreasing pH of acid rain, the individual number and biodiversity indices of the animals decreased. When the acid rain pH fell to 3.0, the total individual number and the diversity indices of the animals had a significant difference with those of the control. Our results also showed that the test soil animals had a trend to move down to the deeper soil layers under the impacts of acid rain.

Key words: Huolin River catchment wetland Soil organic carbon, Total nitrogen, Spatial distribution characteristics, Ecological effect